class ImageEffectDeleteForm

class ImageEffectDeleteForm extends ConfirmFormBase {
    
    /**
     * The image style containing the image effect to be deleted.
     *
     * @var \Drupal\image\ImageStyleInterface
     */
    protected $imageStyle;
    
    /**
     * The image effect to be deleted.
     *
     * @var \Drupal\image\ImageEffectInterface
     */
    protected $imageEffect;
    
    /**
     * {@inheritdoc}
     */
    public function getQuestion() {
        return $this->t('Are you sure you want to delete the @effect effect from the %style style?', [
            '%style' => $this->imageStyle
                ->label(),
            '@effect' => $this->imageEffect
                ->label(),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfirmText() {
        return $this->t('Delete');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCancelUrl() {
        return $this->imageStyle
            ->toUrl('edit-form');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'image_effect_delete_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state, ImageStyleInterface $image_style = NULL, $image_effect = NULL) {
        $this->imageStyle = $image_style;
        $this->imageEffect = $this->imageStyle
            ->getEffect($image_effect);
        return parent::buildForm($form, $form_state);
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $this->imageStyle
            ->deleteImageEffect($this->imageEffect);
        $this->messenger()
            ->addStatus($this->t('The image effect %name has been deleted.', [
            '%name' => $this->imageEffect
                ->label(),
        ]));
        $form_state->setRedirectUrl($this->imageStyle
            ->toUrl('edit-form'));
    }

}